The lid assembly may comprise two separate parts arranged to fit over respective parts of the opening and be removably secured to the flange members, the two parts of the assembly, when fitted, together closing off less than the entire opening.
With this construction, during normal use, the lid assembly is secured to the vessel and molten metal is transferred into and out of the vessel through the part of the opening which is not closed by the lid assembly. When it is necessary to replace the refractory lining, the lid assembly is detached from the flange members and removed thereby exposing the entire opening in the wall of the vessel. A large portion of the refractory brickwork is also exposed and this can very quickly be wrecked from outside exposing a large area of the interior of the vessel. The opening is of sufficient size to enable personnel and materials to readily enter into and leave the elongate vessel.
The removal of the refractory brickwork below the lid assembly permits rapid cooling of the refractory material and the brickwork can be removed speedily by the appropriate mechanical equipment, operating through the large opening in the wall of the vessel. The vessel remains attached to its bogie assemblies and it can be tilted to ease access into the vesel and rubble produced during the wrecking operation can be removed simply by rotating the vessel to allow the rubble to fall through the opening.
In order to replace the refractory material, the lower part of the vessel can be relined before the lid assembly is refitted. The remaining part of the relining takes place after the lid asembly has been fitted and a spout opening is formed in refractory material in the opening not covered by the lid assembly. Alternatively, the lid assembly can be replaced immediately when the old lining has been removed and the entire new lining provided subsequent to the re-positioning of the lid assembly.
If distortion of the lid assembly occurs during use of the torpedo car, a replacement assembly can be readily fitted to the car to return it to service as soon as possible and repairs to the original lid assembly can be carried out away from the torpedo car.